Green Optics그린광학

Green Optics has shares down about a third over the past month, while its filings show a small profit but heavy negative free cash flow.

Green Optics is a Korean precision optics maker that sells zinc sulfide optical components to defense, display, semiconductor inspection and aerospace customers. As of 30 October 2026 the share price is ₩9,830, well below its 52-week high of ₩55,000, and the market value is about ₩115B. Trailing figures to H1 2026 show revenue of ₩41.8B, operating income of ₩2.2B and net income of ₩2.0B, with borrowings of ₩17.6B against cash of ₩2.9B.

What stands out

• Trailing revenue of ₩41.8B with a 5.3% operating margin and 4.9% net margin, and ROE of 3.1%.
• Free cash flow is about -₩18.9B on a trailing basis, far larger than the reported profit, and borrowings of ₩17.6B exceed cash of ₩2.9B.
• Share price returns are -32.6% over one month and -25.1% over three months; the one-year return is not available in the data.
• Trailing P/E is 56.2 and P/B is 1.7, above several listed peers such as Kctech, Classys and TSE on P/E, though the peer set is small and the data gives no fair value estimate.
• Recent filings include two major sales or supply contracts (June and August 2026) and a half-year report for June 2026; the data shows no recent news headlines.

What to watch

• The next quarterly or half-year results, to see whether free cash flow and borrowings improve from current levels.
• Further filings on major sales or supply contracts and any changes to revenue or profit structure.
• Continued foreign selling: foreign ownership fell from 6.4% to 5.7% over 60 days, and the 20-day flows show net foreign and institutional selling.